A conventional rotational angle detection apparatus includes a permanent magnet and a pair of yokes rotatable relative to each other, a pair of magnetic collection rings that guides a magnetic flux generated between the pair of yokes due to the relative rotation between the permanent magnet and the pair of yokes, and a Hall IC sensor that detects the magnetic flux between the magnetic collection rings. The pair of yokes and the pair of magnetic collection rings, which are a detection member, are each made from a soft magnetic material, such as a permalloy, and are formed integrally with a resin holder by insert-molding formation and fixed to an input/output shaft or a housing via the holder. PTL 1 discusses one example relating to the above-described technique.